The History of the Technical Implementation of the 3D-Representation of the Digital Earth

A distinctive feature of the Digital Earth project is implementation a three-dimensional model of the Earth while simultaneously realizing such properties as multiscale and 3D-representation. The approaches that make it possible to realize the possibility of representing our planet from various angles are considered. The essence of the discrete global grid system method is outlined, as well as possible projection methods. A brief technical description of the method is provided with historical points of origin and descriptions. An effective way of working with data, preferred for the Digital Earth, is indexing, implemented using three methods \u2013 hierarchy, a curve filling the space and based on axes. Examples of the use of grid systems are given alongside the specifics of their application.